Effect of Corrosion and Corrosion Rate on the Mechanical Performance of Carbon and Stainless Steel Reinforcing Bars

Steel corrosion is a predominant factor leading to age-related structural degradation. To understand the different effects of pitting corrosion on the mechanical performances of deformed carbon and stainless steel reinforcing bars, an artificially accelerated method was conducted to corrode the steel bars. Using a 3D laser scanner, the three-dimensional models of corroded steel bars were reconstructed. The corrosion characterization was identified based on these 3D profiles. The results indicate that the number and the depth of corrosion pits of both types of steel increase with the increase of corrosion rate, however the pitting corrosion of stainless steel is much more obvious than the carbon steel. Axial tensile tests of corroded carbon and stainless steel bars were carried out. The tensile test results show that both the yield and ultimate loads linearly decreased with an increase of corrosion loss while the ductility decreased correspondingly. With the increase of corrosion loss, brittle fracture gradually occurred in the corroded carbon steel bars at the location of critical cross-sectional area. However, the degradation ratio of elongation of stainless steel is less than that of the carbon steel.